feat(cli): add subcommand completion to generate various shell completions (#6313)

Signed-off-by: Sai Karthik <kskarthik@disroot.org>

Cargo.lock

@@ -1430,6 +1430,15 @@ dependencies = [
  "terminal_size",
 ]
 
+[[package]]
+name = "clap_complete"
+version = "4.5.62"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "004eef6b14ce34759aa7de4aea3217e368f463f46a3ed3764ca4b5a4404003b4"
+dependencies = [
+ "clap",
+]
+
 [[package]]
 name = "clap_derive"
 version = "4.5.49"
@@ -3078,6 +3087,7 @@ dependencies = [
  "bat",
  "chrono",
  "clap",
+ "clap_complete",
  "cliclack",
  "console 0.16.2",
  "dotenvy",